JP3536276B2 - Foundation pile - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation pile forming a foundation of a structure.

[0002]

2. Description of the Related Art As is well known, there is a foundation type of a structure in which a plurality of foundation piles are constructed in the ground.

By the way, when a strong earthquake or the like occurs, excessive bending moment or shearing force acts on the foundation piles, which damages the foundation piles or causes the foundation piles to flow laterally due to liquefaction of the ground. It may be damaged. The foundation pile damaged in this way is lacking in soundness and cannot be said to have the original function.

Therefore, when a structure is damaged by a disaster, not only the main body of the structure but also the foundation and the piles are damaged, and if there is damage, the degree of damage is checked to confirm the soundness. Then they need to be repaired if necessary. It is relatively easy to confirm the soundness of the structure body exposed on the ground, but it is difficult to confirm the soundness of the foundation piles buried in the ground. For this reason, conventionally, the amount of subsidence and unequal subsidence of structures is measured, or the ground is excavated to expose the pile head and the deformation of the foundation pile is visually observed. Is.

[0005]

However, the above-mentioned conventional techniques have the following problems.
That is, in the method for confirming the soundness of foundation piles by measuring the amount of subsidence or unequal subsidence, except for the case where an abnormality is apparent, or when the subsidence or unequal subsidence is clearly above the reference value, it is necessary to recover. Cannot be a sufficient judgment material. In addition, observation of only the pile head does not provide sufficient information about the deformation of the pile in the ground. For this reason, it is difficult to accurately determine the soundness of the foundation pile when, for example, no deformation is found in the pile head and the overall settlement or inclination of the structure is slight. In such a case, even if the middle part or the lower part of the foundation pile is actually damaged, there is a possibility that the damage cannot be found or confirmed, and the recovery may be left as it is.

In order to avoid such problems, various techniques for judging the soundness of foundation piles have been developed in recent years. For example, a pile impact judgment method, which is one of nondestructive inspection methods, has been developed. is there. In this technology, a sensor is placed around the pile head, the pile head is hit, and at this time the reflected wave that propagates in the pile body is detected by the sensor, and the soundness of the pile is judged from its properties. Is what you are trying to do. But,
Even with this method, due to cost and labor problems,
Except for the foundation piles located on the outer edge of the foundation, it is practically difficult to conduct the survey, and reliable judgment data cannot be obtained in all cases. Moreover,
Needless to say, it is desired that the soundness survey be conducted as soon as possible in order to achieve prompt recovery after the disaster.

The present invention has been made in consideration of the above points, and provides a foundation pile capable of conducting a highly reliable investigation of the soundness of the foundation pile at low cost quickly and simply. This is an issue.

[0008]

The invention according to claim 1 is
Inside the foundation pile built in the ground, from its upper end to its lower end, a conductive wire whose electrical resistance value changes depending on the history of load and strain, at least its both ends from the upper end of the foundation pile. embedded by extending outward Rutoto
At the designated section of the foundation pile, a cylindrical guide pie is used.
And the conductive wire is placed in the front of the section.
It is inserted in the guide pipe, and even when an earthquake occurs
Damage such as damage of the conductive wire in the guide pipe
It is characterized by being configured not to receive .

According to a second aspect of the present invention, a conductive wire having conductivity and having an outer peripheral surface covered with an insulating material is provided inside at least one end of a foundation pile constructed in the ground. the embedded by extending outward from the upper end of the foundation pile Rutotomoni, tubular to the a defined foundation pile section
Guide pipe is provided, and the conductive wire is connected to the section.
In the case of an earthquake
Even in the case where the conductive wire is in the guide pipe,
It is characterized by a structure that does not suffer damage such as damage .

According to a third aspect of the present invention, in the foundation pile according to the second aspect, the conductive wire has mechanical properties such as yield stress, tensile strength and breaking stress of the reinforcing bars constituting the foundation pile. It is characterized in that a material having a breaking stress or a tensile strength set based on the material is used.

The invention according to claim 4 is the invention according to claim 2 or 3.
In the above described foundation pile, the defined section of the conductive wire is formed of a material having a strength higher than the strength of the reinforcing bars constituting the foundation pile.

The invention according to claim 5 relates to claims 1 to 4.
In the foundation pile according to any one of the above, in the foundation pile, a plurality of the conductive wire rods, each extending in the vertical direction, the interval determined in the circumferential direction with respect to the central axis of the foundation pile. The feature is that they are arranged separately.

The invention according to claim 6 is defined by claims 1 to 5.
In the foundation pile according to any one of, the conductive wire is
It is divided into multiple sections, and the wiring cable is
One end is connected, and the other end of the wiring cable is connected to the foundation pile.
It is characterized by being extended outward from the upper end of the.

The invention according to claim 7 relates to claims 1 to 6.
In the foundation pile according to any one of above, the conductive wire rod
Is a cylindrical container filled with a plurality of conductive particles.
Container or outer surface is coated with an insulating material
It is characterized in Rukoto such from the tape material to be.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, examples of first to seventh embodiments of a foundation pile according to the present invention will be described with reference to FIGS. 1 to 15.

[First Embodiment] First, the structure of the foundation pile according to the present invention will be described with reference to an example in which it is applied to a foundation pile made of prestressed concrete.

As shown in FIG. 1, the foundation pile 1 is made of, for example, a ready-made centrifugal force prestressed concrete construction, the shape thereof is a bottomed cylindrical shape, and the diameter of the bottom portion, that is, the lower end portion is gradually reduced. It is said that.

In such a foundation pile 1, four conductive cables (conductive wire rods) 2, 2, ... Are respectively provided at equal intervals (every 90 °) in the circumferential direction of the cross section, respectively. In order to extend in parallel with, it is embedded along with a reinforcing bar or the like not shown in the concrete constituting the pile body 1a of the foundation pile 1. The upper end of each of the conductive cables 2, 2, ... Is pulled out from the upper end of the foundation pile 1. In addition, the conductive cables 2A and 2B, 2C and 2D facing each other with the central axis of the foundation pile 1 interposed therebetween,
The lower ends of the foundation piles 1 are connected to each other. This allows the conductive cables 2A and 2B, 2C and 2
D is arranged in a substantially U shape, and both ends thereof are drawn out from the upper end of the foundation pile 1.

The conductive cable 2 is a wire made of a composite material of a reinforced plastic made of a resin such as epoxy and vinyl ester, and a reinforcing material of a fiber bundle made by bundling carbon fiber and glass fiber, respectively. It has a property that the electric resistance changes when a load due to the strain acts and a certain amount of strain occurs. For example, in the case of carbon fiber, when the strain occurs, the fiber is gradually broken, and eventually the fiber is completely broken. In this process, the conductivity is lowered and the electric resistance value is gradually increased. Eventually it will be significantly higher.

By the way, as shown in FIG. 2, when such a foundation pile 1 is spliced, at the joint portion A between the upper end of the foundation pile 1 and the lower end of the pile 1'for splicing, The end of the conductive cable 2 is drawn inward from the upper end of the foundation pile 1 and the inner surface of the lower end of the pile 1'for splicing, and the upper end of the conductive cable 2 on the lower foundation pile 1 side is connected. ,
The upper end of the pile 1'for splicing is connected to the lower end of the conductive cable 2 by an adhesive having conductivity.

As shown in FIG. 3, a marking M is provided on the outer surface of the foundation pile 1 at a position where each conductive cable 2 is embedded. This marking M is
It is composed of a line L drawn along each conductive cable 2 and a symbol S such as a number for identifying each conductive cable 2, for example, conductive cables 2A, 2B, 2C, 2D are buried. The positions are "red", "blue", and
"Yellow" and "Black" lines L and "1", "2",
The symbols S of "3" and "4" are written.

If the foundation pile 1 is a small-scale structure, it is desirable that all of the foundation piles 1 are the foundation piles 1.
On the other hand, in the case of a large-scale structure in which the number of piles is very large, the foundation pile 1 may be appropriately arranged in a part thereof. In this case, for example, as shown in FIG. 4, the foundation piles 1 are preferentially arranged on the outer peripheral edge portion of the foundation 5 where the load of seismic force is large. In addition, when the structure's center of gravity and rigid center do not match and a torsional response of the structure is expected during an earthquake, etc., the position where the load concentrates and acts with the vibration characteristics of the structure taken into consideration. The foundation pile 1 should be placed in the center.

Next, a method of investigating the soundness using the foundation pile 1 will be described. As shown in FIG. 5, in such a foundation pile 1, for example, after a strong earthquake occurs, the conductive cables 2A and 2B pulled out from the upper ends thereof.
An electric tester 6 is connected to both end portions of and the electric resistance value is measured. Then, when the foundation pile 1 is broken, the conductive cable 2B is also cut at the breakage point H. In this case, the electric resistance value of the electric tester 6 is significantly increased, and the foundation pile is damaged. It is judged that breakage occurred in No. 1. In addition, the conductive cables 2A, 2
Even if B is not completely broken, the carbon fiber is damaged due to the load acting on the foundation pile 1 and the strain generated by this load, and the electrical resistance value is increased, which causes some damage to the foundation pile 1. You can judge that
On the other hand, if the foundation pile 1 is not damaged, the electric resistance values of the conductive cables 2A and 2B in the electric tester 6 are the same as the initial values.

By performing the same investigation on the conductive cables 2C and 2D connected to each other, the investigation of the soundness of one foundation pile 1 is completed.

After investigating the presence or absence of damage to all the foundation piles 1 arranged on the foundation 5 shown in FIG. 4 as described above, repairing the damaged portion H of the damaged foundation piles 1. To be done by the most suitable means.

In the foundation pile 1 described above, a conductive cable 2 extending vertically is embedded in the foundation pile 1, and the conductive cables 2A and 2B facing each other with the central axis of the foundation pile 1 interposed therebetween are provided.
2C and 2D are connected to each other, and both ends thereof are drawn outward from the upper end of the foundation pile 1. In the foundation pile 1 having such a structure, when the foundation pile 1 is damaged due to an earthquake or the like, the conductive cable 2 is damaged, fractured, the load acting is changed, or distorted. By measuring the electric resistance value of the flexible cable 2, the soundness of the foundation pile 1 can be objectively and quantitatively investigated. Moreover, such a highly reliable survey of the soundness of the foundation pile 1 shows that regardless of the position of the foundation pile 1, even if the location of the damage is other than the pile head of the foundation pile 1, the foundation Simple electric tester 6 on the head of pile 1
Can be used easily and simply at an extremely low cost, and as a result, recovery can be speeded up.

Further, the conductive cables 2A, 2B and 2C which are opposed to each other and are connected to each other with the central axis of the foundation pile 1 interposed therebetween.
Since 2D and 2D are arranged at equal intervals in the circumferential direction, that is, at every 90 °, the soundness in two horizontal directions orthogonal to each other in the foundation pile 1 can be investigated. Therefore, by installing the conductive cables 2A and 2B, 2C and 2D of the foundation pile 1 in accordance with the directionality of the structure, for example, the difference in vibration characteristics and seismic response in the longitudinal direction and the lateral direction Can also be taken into account and the survey can be made more effective. At this time, since the marking M indicating the position and identification of the conductive cables 2A, 2B, 2C, and 2D is provided on the outer peripheral surface of the foundation pile 1, the directionality of the foundation pile 1 when the foundation pile 1 is built. It is possible to perform the construction easily and surely by checking.

In the first embodiment, the foundation pile 1 has a hollow cylindrical shape with a bottom, but it goes without saying that the entire cross section may be solid prestressed concrete.

[Second Embodiment] Next, the structure of the foundation pile according to the present invention will be described with reference to an example in which it is applied to a foundation pile made of cast-in-place concrete. In these figures, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 6, the foundation pile 11 is made of cast-in-place concrete, and the pile body 11a is composed of a rebar cage 12 assembled in a substantially cylindrical shape and concrete 13. For example, four conductive cables 2, 2, ... Are embedded in the foundation pile 11 so as to extend in the vertical direction along the rebar cage 12.

When constructing the foundation pile 11, after drilling a hole in the ground, a rebar cage 12 is installed in this hole.
After installing these conductive cables 2, 2, ..., Concrete may be placed in the holes.

The foundation pile 11 described above can also achieve the same effect as that of the foundation pile 1 in the first embodiment.

[Third Embodiment] Next, the structure of the foundation pile according to the present invention will be described with reference to an example in which it is applied to a foundation pile made of, for example, a steel pipe. In these figures, the same components as those in the first and second embodiments are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 7, the foundation pile 21 is made of steel pipe, and the pile body 21a made of steel pipe has, for example, 4
.. are arranged so as to extend in the vertical direction. Each conductive cable 2 has a pile frame 21.
It is housed in a substantially U-shaped case 22 attached to the inner surface of a, and the case 22 protects each conductive cable 2 from damage during construction.

The foundation pile 21 described above can also achieve the same effects as the foundation pile 1 in the first embodiment.

In the third embodiment, the case 22 is attached to protect the conductive cables 2. However, the case 22 may be attached if necessary, and is not always required. It is not composed of.

[Fourth Embodiment] Next, a fourth embodiment of the foundation pile according to the present invention will be described. Here, description will be given using an example in which a guide pipe is arranged in a predetermined section of the foundation pile and a conductive cable is inserted into the guide pipe. In these figures, the same components as those in the first to third embodiments are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 8, the foundation pile 31 has a pile body 31a having the same shape as the pile body 1a of the foundation pile 1 of the first embodiment. Four conductive cables 2, 2, ... Are arranged and buried every 90 ° in the circumferential direction.

Of these four conductive cables 2, two conductive cables 2E and 2F adjacent to each other are arranged only in the upper half so that the tip ends thereof are located in the middle of the foundation pile 31. ing. The remaining two conductive cables 2G and 2H are arranged over the entire length of the foundation pile 31. These conductive cables 2G and 2H are the foundation piles 31.
Is inserted in the tubular guide pipe 32 in the upper half part, that is, in the section corresponding to the conductive cables 2E and 2F. Each of the guide pipes 32 has sufficient strength and flexibility, and prevents the conductive cables 2G and 2H in the guide pipes 32 from being damaged even when the foundation pile 31 is damaged by an earthquake or the like. It is like this.

In the foundation pile 31 described above, as in the foundation pile 1 in the first embodiment, the conductive cables 2E,
2F, 2G, 2H makes it possible to easily and simply investigate the soundness of the foundation pile 31 with high accuracy. Moreover,
The conductive cables 2E and 2F are arranged only in the upper half part of the foundation pile 31, and the conductive cables 2G and 2H arranged along the entire length of the foundation pile 31 are connected to the guide pipe 32 in the upper half part of the foundation pile 31. It is configured to be inserted inside.
Thus, the soundness of the upper half of the conductive cables 2E, 2F and the lower half of the conductive cables 2G, 2H can be investigated. Even if the foundation pile 31 is damaged during an earthquake, the conductive cables 2G and 2H can be prevented from being damaged in the section of the guide pipe 32.

Although the guide pipe 32 is arranged in the upper half portion of the foundation pile 31 in the fourth embodiment, the section where the guide pipe 32 is installed may be arbitrarily set.

In the first to fourth embodiments described above, a reinforcing member of a fiber bundle in which, for example, carbon fibers and glass fibers are bundled in the conductive cable 2,
A composite material of reinforced plastics made of a resin such as epoxy or vinyl ester is used, but other than this, any material whose electric resistance value changes depending on the load or the amount of strain can be adopted. In addition, such a conductive cable 2 made of a composite material of reinforced plastics made of a resin such as epoxy or vinyl ester and a reinforcing material of a fiber bundle made by bundling carbon fiber and glass fiber, respectively, is Since it is possible to manufacture it by arbitrarily changing the strength or the critical strain value, etc., by appropriately setting those set values, the foundation piles 1, 11, 2,
It is possible to make a determination not only for the breakage of Nos. 1 and 31 but also for cracks, for example. Furthermore, by embedding a plurality of types of conductive cables 2 having different set values such as strength or limited strain value in the foundation pile 1, it is possible to determine the degree of damage to the foundation pile 1 such as cracking or breaking. It is also possible to do.

Further, the conductive cable 2 may be embedded in the foundation piles 1, 11, 21, 31 as an alternative to the conventional reinforcing bar. With such a configuration, the conductive cable 2 not only functions as a soundness monitor but also has a reinforcing function, and further, with the carbon fiber that constitutes such a conductive cable 2, The composite material of the reinforced plastics made of the resin such as epoxy and vinyl ester and the reinforcing material of the fiber bundle in which the glass fibers are respectively bundled is the conventional material such as the place where the groundwater containing the chemical substance and its components exists. If it is a reinforcing bar, the foundation pile 1 can be constructed even in a place where there is a concern about corrosion.

[Fifth Embodiment] Next, a fifth embodiment of the foundation pile according to the present invention will be described. Here, an example of using a reinforcing bar as the conductive wire will be described. In these figures, the same components as those in the first to fourth embodiments are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 9, the foundation pile 41 is made of reinforced concrete, and the shape of the pile body 41a itself is the same as that of the pile body 1a (see FIG. 1) of the foundation pile 1 of the first embodiment. In the pile body 41a, for example, four conductive wires 42, 42, ... Having conductivity are arranged and buried every 90 ° in the circumferential direction.

The conductive wires 42, 42 facing each other across the central axis of the foundation pile 41 are connected to each other at the lower end of the foundation pile 41. As the conductive wire 42, a wire having the same mechanical properties as the structural reinforcing bars (reinforcing bars) 43, 43, ... Constituting the foundation pile 41, for example, the same reinforcing bar as the structural reinforcing bar 43 is used. . The outer peripheral surface of each conductive wire 42 is covered with an insulating material 44 such as plastics or resin having a high insulating property. For connecting the conductive wires 42, various connection methods such as welding and mechanical connection methods can be used as long as they can maintain conductivity.
Electrical connection may be made after connection.

In this foundation pile 41, after a strong earthquake, for example, the electric resistance values of the conductive wires 42, 42 are measured by the electric tester 6 (see FIG. 5), as in the above-described embodiments. To do. If the conductive wire 42, that is, the reinforcing bar is broken, the electric resistance value is significantly increased. At this time, the surrounding structural reinforcing bar 43 having the same mechanical properties is also broken or seriously damaged in the vicinity thereof. You can judge that

According to the foundation pile 41 described above, the presence or absence of damage can be detected by the conductive wire rod 42 having the same mechanical properties as the structural reinforcing bar 43, that is, the reinforcing bar.
Therefore, the same effects as those of the first to fourth embodiments can be obtained, and the soundness of the foundation pile 41 can be easily performed with high reliability. Moreover, a reinforced plastic made of a resin such as epoxy or vinyl ester, which is a reinforcing material of a fiber bundle formed by bundling carbon fiber and glass fiber used as the conductive cable 2 in the first to fourth embodiments. According to the present embodiment in which the reinforcing wire is used as the conductive wire 42, the above-described effects can be realized at a significantly lower cost, as compared with a composite material such as stainless steel.

In the fifth embodiment, the conductive wire 42 is made of a material having the same mechanical properties as the structural rebar 43. By the way, the mechanical properties (yield point or proof stress, tensile strength, elastic constant, etc.) of the reinforcing bar used for the structural reinforcing bar 43 are specified in JIS standard (steel rod for reinforced concrete of JIS G3112), and tensile stress- The distortion curve is as shown in FIG. In this curve (reference numeral (a) in FIG. 10), as is well known, two characteristic points are a yield point (yield stress) and a fracture extension point (fracture point) related to toughness.

In the fifth embodiment, the conductive wire 42 is made of a material having the same mechanical properties as the structural reinforcing bar 43, so that the conductive wire 42 is broken, that is, the break point is reached. It is designed to detect whether or not it has been done. Here, as the material of the conductive wire 42, one having a small spread to break is selected. further,
Here, for example, as the conductive wire 42, a material whose tensile strength is equal to or lower than the yield stress of the structural rebar 43 (shaded area in FIG. 10) may be selected and adopted. good. With this configuration,
After the occurrence of an earthquake or the like, the electric resistance value of the conductive wire 42 is measured, and if the conductive wire 42 is broken, that is, the structural rebar 43 exceeds the yield point or is close to it even before it breaks. It can be judged that the stress is applied. To give a more specific example of the material, for example, structural rebar 43
In the case of using a steel bar for reinforced concrete / deformed steel bar SD295A, the yield point is 3008 kgf / cm ² . Therefore, as the material of the conductive wire 42, a material having a spread of about 5% or less and a tensile strength of about 3000 kgf / cm ² (indicated by a symbol (b) in FIG. 10), for example, a 5000 series aluminum alloy ( Al-Mg alloy) and aluminum forgings,
Aluminum alloy wrought material, magnesium cast product, etc. may be adopted.

Also, when the conductive wire 42 made of the reinforcing bar is used, similarly to the fourth embodiment, a guide pipe is provided in a predetermined section to check the soundness of the foundation pile 41 for each part. It is also possible to adopt a configuration in which it is performed.

[Sixth Embodiment] Next, a sixth embodiment of the foundation pile according to the present invention will be described. Here, description will be made using an example in which a part of the conductive wire has a higher strength than the reinforcing bars constituting the foundation pile. In these figures, the same components as those in the first to fifth embodiments are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 11, the foundation pile 51 is made of reinforced concrete, and in the pile body 51a, for example, four electrically conductive wires 52, 52, ...
It is arranged and buried every 0 °. Each conductive wire 52
The outer peripheral surface thereof is covered with an insulating material 53 such as plastic or resin having high insulating properties.

Of these four conductive wire rods 52, the two conductive wire rods 52A and 52B adjacent to each other are arranged only in the upper half portion so that the tips thereof are located in the middle portion of the foundation pile 51. ing. In addition, the remaining two conductive wires 52
C and 52D are arranged over the entire length of the foundation pile 51. Then, the lower half portions of the conductive wire rods 52A and 52B and the conductive wire rods 52C and 52D are formed by reinforcing bars having the same mechanical properties as the structural reinforcing bars (reinforcing bars) 54 forming the foundation pile 51.

The conductive wires 52C and 52D are the foundation piles 51.
The upper half part, that is, the section H corresponding to the conductive wires 52A and 52B, is electrically conductive and is superior in mechanical properties, particularly strength and elongation, to the structural reinforcing bars 54 constituting the foundation pile 51. , For example, high strength steel or tough steel. Here, when the steel bar / deformed steel bar SD295A for reinforced concrete is used as the structural rebar 54, the high-strength steel has a tensile strength of about 5100 kgf / cm ² or more, or a yield point or a yield strength of about 3100 kgf / cm ^2. Above, the steel material excellent in weldability and low temperature toughness is used. Further, the tough steel refers to a steel having high strength and excellent toughness, and is 0.25 to
Carbon steel containing about 0.5% carbon, low alloy steel containing Mn, Cr, Mo, Ni, etc. alone or in combination in addition to the above amount of carbon, and the like.

According to the foundation pile 51 described above, the foundation pile 51
The soundness of the upper half part can be checked by the conductive wire rods 52A and 52B, and the soundness of the lower half part can be checked by the conductive wire rods 52C and 52D. Moreover, when the conductive wires 52A and 52B and the lower half portions of the conductive wires 52C and 52D are broken or damaged due to an earthquake or the like, the conductive wires 52C and 52D are broken.
Since the upper half of D is made of a material having high mechanical properties, it is possible to reliably transmit the information about the presence or absence of breakage and damage of the lower half to the head of the foundation pile 51 without breaking. it can.

[Seventh Embodiment] Next, a seventh embodiment of the foundation pile according to the present invention will be described. Here, description will be given using an example in which the conductive wire is divided into a plurality of sections and the soundness is investigated for each section. In these figures, the same components as those in the first to sixth embodiments are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 12, the foundation pile 61 is made of reinforced concrete, and four conductive wires 62 (only one of which is shown) having conductivity are provided in the circumferential direction 90 in the pile body 61a. It is arranged and buried every °. Each conductive wire rod 62 is a structural reinforcing bar (reinforcing bar;
It is formed of a reinforcing bar having the same mechanical properties (not shown), and its outer peripheral surface is covered with an insulating material 63 such as plastic or resin having a high insulating property. Each conductive wire 62 has, for example, four sections (a) in the vertical direction,
(B), (c), and (d), and the distribution cables 64a, 64b, 64c, 64 are located at the partition points of each section.
One end of d is connected. These wiring cables 64
a, 64b, 64c, 64d pass through the guide pipe 65 embedded in the pile body 61a to protect them, and are wired to the head of the foundation pile 61, and terminals (not shown) are provided at the respective ends. It is equipped.

According to such a foundation pile 61, when an integrity of the foundation pile 61 is investigated after an earthquake or the like, for example,
By measuring the electrical resistance value between the terminal 62a provided on the head of the conductive wire 62 and the terminal (not shown) of the wiring cable 64a, the soundness of the section (a) can be investigated. In this way, the terminal 62a on the head of the conductive wire 62 and the wiring cables 64a, 64b, 64
If the electrical resistance between the terminals (not shown) provided at the ends of c and 64d is measured, the soundness of the conductive wire 62 is measured in each section (a), (b), (c), (d). ) Can be investigated.

In the seventh embodiment, as the conductive wire 62, for example, a structural reinforcing bar is used, but it goes without saying that the carbon fiber and glass as shown in the first to third embodiments are used. A composite material such as a composite material of a reinforced plastic made of a resin such as epoxy or vinyl ester and a reinforcing material of a fiber bundle in which fibers are bundled may be used.

In the first to seventh embodiments, the foundation piles 1, 11, 21, 31, 41, 51, 6 are used.
1. Conductive cable 2 or conductive wire 4 arranged in 1
The number of 2,52,62 is not limited to four,
It may be set arbitrarily. Further, for example, instead of these four conductive cables 2, 2, ..., One conductive cable may be arranged continuously. Further, the conductive cable 2 and the conductive wire rods 42, 52, 62 are configured to extend in the vertical direction.
It is effective for lateral cracking of 11, 21, 31, 41, 51, 61 (crack extending in the direction orthogonal to the axis). When this is effective for vertical cracking, the conductive cable 2 and the conductive wire members 42, 52, 62 are treated like hoop streaks.
You may make it extend in the circumferential direction in the surface orthogonal to the axis line of the foundation pile 1,11,21,31,41,51,61,
It may be arranged in a spiral shape. Needless to say, the hoop-shaped or spiral conductive cable and the conductive cable 2 extending in the vertical direction may be combined and employed.

Further, the foundation piles 1, 11, 21, 31,
The cross-sectional shapes of 41, 51, 61 are not limited to the above, and may be rectangular in cross-section, or hollow or solid. In addition, the number and the arrangement of the foundation piles 1, 11, 21, 31, 41, 51, 61 including the conductive cables 2 and the conductive wires 42, 52, 62 are not limited at all.
It may be set appropriately according to the total cost.

[Other Embodiments] Next, still another embodiment of the foundation pile according to the present invention will be described. In the first to seventh embodiments, as the conductive wire, a reinforcing material for a fiber bundle in which carbon fibers and glass fibers are bundled, and a reinforced plastics made of a resin such as epoxy or vinyl ester is used. An example of using a composite material such as a composite material or a steel rod such as a structural reinforcing bar has been described, but another material that can be used as the conductive wire will be described here. In addition, the conductive wire made of still another material described below is the foundation pile 1, 11, 21, 31, shown in the first to seventh embodiments.
41, 51, 61 conductive cable 2, conductive wire 4
Since it may be used in place of 2, 52, 62, the description of the structure of the other parts of the foundation pile will be omitted.

As shown in FIG. 13, foundation piles 1, 11, 2
The conductive member (conductive wire) 71 used for 1, 31, 41, 51, 61 is made of a conductive tape material 71a, and the outer peripheral surface thereof is covered with an insulating material 71b such as plastics or resin. Has been done. Then, terminals 72, 72 are provided at the upper and lower ends thereof, and wirings for measuring an electric resistance value and another conductive member 71 are connected to these terminals. Conductive tape material 7
1a is, for example, a metal foil of copper, aluminum or the like having good conductivity, a tape material having conductivity, for example, a polymer material such as metal or its oxide, and carbon (carbon graphite or carbon black) or the like. It is possible to use those in which fine particles are mixed, those in which ultrafine metal particles are adhered to a plastic film (for example, video tapes are preferable because they are inexpensive and easily available).
Even with such a conductive member 71, by applying to the foundation piles 1, 11, 21, 31, 41, 51, 61 instead of the conductive cable 2 or the conductive wires 42, 52, 62, these It becomes possible to investigate the soundness.

In the conductive member (conductive wire) 73 shown in FIG. 14, a conductive tape material 73a is arranged in a substantially U shape, and this is an insulating material 73b such as plastics or resin. It is covered and has a linear shape as a whole. Then, both ends of the tape material 73a are connected to the conductive member 7a.
It is arranged so as to project from the head of 3, and here,
Terminals 74 and 7 for connecting wiring for measuring electric resistance
4 are provided. According to such a conductive member 73, like the above-mentioned conductive member 71, instead of the conductive tape 2 and the conductive wire rods 42, 52, 62, foundation piles 1, 11,
By applying to 21, 31, 41, 51, 61,
It is possible to investigate these soundness. Moreover,
Since the electrically conductive tape material 73a is arranged in a substantially U shape, the terminals 74, 74 can be arranged at the upper end portion. Therefore, as in the first to seventh embodiments, Conductive tape 2 and conductive wire 4 facing each other
One conductive member 73 is connected to the foundation piles 1,11,21,31, without connecting 2,52,62 into a substantially U-shape.
The soundness can be investigated only by embedding it at a predetermined position of 41, 51, 61. Thereby, the conductive member 73 can be easily installed.

Further, the conductive member (conductive wire) 75 shown in FIG. 15 includes a cylindrical container 76 made of an insulating material such as plastics or resin, and a large number of conductive granular bodies 77. It is a filled structure. And container 7
Terminals 78, 78 electrically connected to the internal granular body 77 are provided at the upper and lower ends of 6. The granular body 77 is formed of a conductive material such as a metal, an oxide, or a carbon material (carbon graphite or carbon black). These granular bodies 77 are, for example, 0.5 mm
Use a smaller diameter. Such a conductive member 75 is used for the conductive tape 2 and the conductive wire rods 42, 52, 6
2 instead of 2, foundation pile 1,11,21,31,41,51,
It should be buried in 61. Then, if the container 76 is damaged due to the damage of the foundation piles 1, 11, 21, 31, 41, 51, 61 due to an earthquake or the like, the granular bodies 77 in the container 76 are damaged from the damaged locations. 21, 31,
It flows out into the cracks 41, 51 and 61, and voids are generated in the container 76. Then, if the electric resistance value of the conductive member 75 is measured in this state, no electric current is applied between the terminals 78, 78, and the electric resistance value becomes extremely high. In this way, the foundation piles 1, 11, 2, also by the conductive member 75.
Damage to 1, 31, 41, 51, 61 can be detected, and soundness can be investigated.

[0067]

As described above, according to the foundation pile of claim 1, the conductive wire is provided inside the foundation pile from the upper end to the lower end, and both ends of the conductive wire are attached from the upper end of the foundation pile. The structure is such that it extends outward and is buried. According to the foundation pile according to claim 2, the inside of the foundation pile is covered with an electrically conductive wire, the outer peripheral surface of which is covered with an insulating material, and at least one end of the foundation wire is extended outward from the upper end of the foundation pile. It was configured to be buried. As a result, if a strong earthquake causes an external force to act on the foundation pile and damage occurs, the conductive wire will also be damaged, fractured, or the applied load will increase or strain will occur. Become. Therefore, after an earthquake or the like, the soundness of the foundation pile can be objectively and quantitatively investigated by measuring the electric resistance value of the conductive wire. Moreover, such a highly reliable survey of the soundness of foundation piles can be performed easily at the pile heads regardless of the position of the foundation piles, and even when the location of the damage is other than the pile head. It can be performed easily and easily using a device at a very low cost, and as a result, restoration can be speeded up. The group according to claim 1 or 2
According to the foundation pile, a cylindrical guide is installed in the prescribed section of the foundation pile.
Place a pipe and connect the conductive wire to the guide pad in that section.
It is configured to be inserted into the ip. As a result, when an earthquake occurs
Etc., the conductive wire may be damaged in the guide pipe.
Can prevent harm. This way guy
By properly setting the section where the pipe is installed,
It is possible to investigate the soundness of only any desired section of the foundation pile
it can.

Further, according to the foundation pile of claim 3,
For the conductive wire rod, a material having a stretch and tensile strength set based on the mechanical properties of the reinforcing bars constituting the foundation pile was used. Thus, for example, if a material having a tensile strength substantially equal to the yield strength of the reinforcing bar forming the foundation pile and a stretchability of about 5% or less is selected and used as the conductive wire, the reinforcing bar will not be broken. Even if it does not exist, it can be detected that it has yielded or is subjected to a large stress close to it.

According to the fourth aspect of the foundation pile, the defined section of the conductive wire rod is formed of a material having strength and toughness higher than the strength of the reinforcing bars constituting the foundation pile. Accordingly, even if the conductive member is broken or damaged in a portion other than the above-mentioned section due to an earthquake or the like, it is possible to prevent the conductive wire rod from being broken or damaged in the section. Therefore, the presence or absence of breakage or damage of the conductive member in the section can be reliably transmitted to the head of the foundation pile, and the soundness of only any desired section of the foundation pile can be investigated. .

According to the foundation pile of claim 5, a plurality of conductive wires are arranged at a predetermined interval in the circumferential direction with respect to the central axis of the foundation pile. This makes it easy to investigate the presence or absence of damage throughout the foundation pile. Moreover, by arranging the conductive wires at 90 ° intervals, the soundness of the foundation pile in two horizontal directions orthogonal to each other can be investigated. Therefore, by installing such foundation piles according to the directionality of the structure, it is possible to consider, for example, the difference in vibration characteristics and seismic response in the longitudinal direction and the lateral direction, and to make the survey more effective. It can be anything.

According to the foundation pile of claim 6, a conductive wire is used.
The material is divided into multiple sections, and a wiring cable is placed at the end of each section.
Connect one end of the wiring cable to the other end of the wiring cable
It has a structure in which Ru is extended outward from the upper end. This allows
Measures electrical resistance between wiring cables at both ends of any section
By doing so, the soundness of only any desired section of the foundation pile can be investigated.

According to the foundation pile of the seventh aspect, the conductive wire rod has a tubular shape filled with a plurality of conductive granular materials .
The container or outer surface is coated with an insulating material
It was configured ing from the tape material having. This ensures that the conductive
By measuring the electrical resistance of the flexible wire ,
It is possible to investigate the soundness.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a foundation pile according to the present invention, and is a plan sectional view (a) and a vertical sectional view (b).

FIG. 2 is a vertical sectional view showing a joint portion of the foundation pile.

FIG. 3 is an elevation view showing an appearance of the foundation pile.

FIG. 4 is a plan view showing an example of the layout of the foundation pile on the foundation of a structure.

FIG. 5 is a vertical sectional view showing a method of investigating the soundness of the foundation pile.

FIG. 6 is a plan sectional view showing a second embodiment of the foundation pile according to the present invention.

7A and 7B are diagrams showing a third embodiment of the foundation pile according to the present invention, and are (a) a plan sectional view and (b) a vertical sectional view.

FIG. 8 is a diagram showing a fourth embodiment of a foundation pile according to the present invention, in which (a) a vertical sectional view, (b) an AA sectional view,
(C) BB sectional drawing.

FIG. 9 is a view showing a fifth embodiment of the foundation pile according to the present invention, and is (a) a vertical sectional view and (b) a plane sectional view.

FIG. 10 is a diagram showing the mechanical properties of the reinforcing bars constituting the foundation pile.

FIG. 11 is a view showing a sixth embodiment of the foundation pile according to the present invention, (a) a vertical sectional view, (b) an AA sectional view,
(C) BB sectional drawing.

FIG. 12 is a vertical cross-sectional view showing a seventh embodiment of the foundation pile according to the present invention.

13A and 13B are an elevation view and a plan sectional view showing another example of the conductive wire used for the foundation pile according to the present invention.

14A and 14B are an elevation view and a plan sectional view showing still another example of the conductive wire used in the foundation pile according to the present invention.

15A and 15B are an elevation view and a plan sectional view showing still another example of the conductive wire used for the foundation pile according to the present invention.

[Explanation of symbols]

1,11,21,31,41,51,61 Foundation pile 2 Conductive cable (conductive wire) 32 Guide pipe 42, 52, 62 conductive wire 44, 53, 63, 71b, 73b Insulating material 43,54 Structural rebar (rebar) 64a, 64b, 64c, 64d wiring cable 71, 73, 75 conductive member (conductive wire)

Front page continuation (72) Inventor Tetsuo Okuno 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (56) Reference JP-A-7-280676 (JP, A) JP-A-8-94557 (JP, A) Registered utility model 3021393 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01L 5/00

Claims (7)

(57) [Claims] 1. A conductive wire material, the electric resistance value of which is changed by a load or a strain from the upper end portion to the lower end portion inside a foundation pile constructed in the ground, at least both ends of the foundation pile. embedded by extending outward from the upper end Rutotomoni, cylindrical gas to the a defined foundation pile section
An id pipe is provided, and the conductive wire is placed in the section.
In addition, it is inserted into the guide pipe, and when an earthquake occurs, etc.
Even if the conductive wire is damaged in the guide pipe,
A foundation pile characterized by being constructed so as not to be damaged . 2. A conductive wire having conductivity and having an outer peripheral surface covered with an insulating material is provided inside a foundation pile constructed in the ground, and at least one end of the conductive wire is an upper end portion of the foundation pile. embedded by extending outward from Rutotomoni, before
Cylindrical guide pipe is installed in the specified section of foundation pile
The conductive wire is in the section in the guide.
Even if an earthquake occurs, the conductive material is inserted through the pipe.
The flexible wire is not damaged in the guide pipe.
Foundation pile characterized by being made into a new structure . 3. The foundation pile according to claim 2, wherein the conductive wire rod has a yield stress of a reinforcing bar constituting the foundation pile,
A foundation pile characterized by using a material having a breaking stress or a tensile strength set based on mechanical properties such as tensile strength and breaking stress. 4. The foundation pile according to claim 2 or 3, wherein the defined section of the conductive wire is formed of a material having a strength higher than the strength of the reinforcing bars constituting the foundation pile. Foundation pile characterized by. 5. The foundation pile according to any one of claims 1 to 4, wherein a plurality of the conductive wire rods extend in the vertical direction on the foundation pile so as to extend along the central axis of the foundation pile. On the other hand, a foundation pile which is arranged at a predetermined interval in the circumferential direction. 6. The foundation pile according to claim 1, wherein the conductive wire is divided into a plurality of sections.
And one end of the wiring cable is connected to the end of each section,
The other end of the wiring cable extends outward from the upper end of the foundation pile.
Foundation pile, characterized in that it is extended. 7. The foundation pile according to claim 1, wherein the conductive material is a plurality of conductive materials .
Cylindrical container filled with granular material, or outer peripheral surface is insulating
Foundation pile, characterized in Rukoto such a tape having a coated conductive material.